Method of cutting quartz crystals and apparatus for preparing quartz crystals for cutting



Aug. 14, 1945. BAKER 7 2,381,993

' METHOD- OF CUTTING QUARTZ CRYSTAL AND APPARATUS FOR PREPARING QUARTZ CRYSTAL FOR CUTTING Filed June 17, 1943 2 Sheets-Sheet 1 mus/v 7'01? 8. E. 84 KER A TTORNE) Aug. 14, 1945. BHE. BAKER 2,381,993

METHOD OF CUTTING QUARTZ CRYSTAL AND APPARATUS FOR PREPARING QUARTZ CRYSTAL FOR CUTTING Filed June 17, 1943 2 Sheets-Sheet 2 INVENTOR 5.5. BAKER ZRD'IM A TTOR/VEV open position;

Patented Aug. 14, 1945 um'rr.1 STATES PATENT orsics HETHOD OF CUTTING QUARTZ CRYS- TALS AND APPARATUS FOR PREPARING QUARTZ CRYSTALS FOR CUTTING Burton E. Baker, Newark, N. J., assignor 'to Western Electric Company, Incorporated, New York, N Y., a corporation of New York Application June 1'7, 1943, Serial No. 491,253 14 Claims. ((1125-12) This invention relates to methods of cutting quartz crystals and apparatus for preparing quartz crystals for cutting.

Quartz crystals are naturally hexagonal in cross-section, providing six natural sides if, during the obtaining of the crystals such as by mining or other methods, the crystals are not broken. However, at times such as these when there is a great demand for such materials, the quartz crystals obtainable may be broken and have several or all of their natural sidesdamaged. In such instances it is extremely difficult not only to support the crystal so as to perform the necessary test in determining the axis thereof but in mounting the crystal for cutting.

Objects of the invention are .to provide a simpie yet highly efllcient method of cutting quartz crystals and apparatus for preparing quartz crystals for cutting,

With these and-other objects in view, the invention comprises an. apparatus by the aid of which the-method may be practised to support an article for movement under test in determining its preferred location with respect to the support, encasing the article in a material anchored to another support to .suspend the article in the material spaced from the supportwhile being moved relative to a cutting element.

Other objects and advantages will be apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein Fig. 1 illustrates an article, such as a quartz crystal, mounted upon a support;

Fig. 2 is a side elevational' view, partially in section, of a unit for testing the article;

Fig. 3 is a. top plan view of the structure shown in Fig. 1 added to a mounting plate in a structure employed to locate the article with its support on the mounting Pl Fig, 4 is a top plan view of a portion of the structure shown in Fig. 3, illustrating the location. of a molding flask about the article;

Fig. 5 illustrates the structure used in marking a portion of the apparatus prior to the molding of the article;

Fig. 6. is a side elevational view of the structure shown in Fig. 5;

Fi '7 is a top plan view of the flask shown in Fig. 8 is a perspective view of the molded article on its mounting plate ready for cutting;

ed article at' the completion of a cut therethrough, and r Fig. 10 is a vertical sectional view of the mounting plate and molded article, illustrating the results of a cut through the molded article.

In preparing the article for cutting, which article in the present instance is quartz crystal, certain tests must be made so that the cuts through the article may be accurate to produce plates cut from the sections thereof having desired characteristics. Therefore, the first test must be made to determine the Z or optic axis of the crystal. This is determined through the aid of the unit shown in Fig. 2, known commercially as a conoscope. This unit includes a tank It including an oil bath I5 through which light rays may be projected from a light source It, the results being visually determined at H through the aid of suitable structures embodied in a portion It. The operator, therefore, selects a crystal I! to be prepared, and may determine the general path of the Z axis by placing the stone in the bath ii in the path of the light, to determine the subsequent mounting position of the crystal as illustrated in Fig. 1.

curately locating it with respect to the support 20 and to retain the crystal in any desired position relative to the support. If desired, the material 23 may be disposed upon the support prior to the original location of the Z axis, so that upon removal of the crystal from the bath of the unit shown in Fig. 2 and the removal of the major portion of the oil clinging to the crystal, the crystal may be disposed in what is presumed ,to be its accurate location in the materiallii with respect to its support.

After this has been accomplished, the crystal is again disposed in the bath, this time with the supporting plate "and its supporting material 23, means being provided, at 25, to locate the supporting plate 20 perpendicular to the lightray and the aperture 22 thereof in central alignment withthe light ray. At this time, observing theeffect of the light my upon the crystal, should the crystal not be accurately located in its material, adjustments may be made during D electric axis of the crystal.

observation, to move the crystal into its accurate position so. that the Z axis of the crystal will be perpendicular to the support 20.

The structure including the crystal shown in Fig. 1 may then be disposed upon an H-shaped element 28 formovement relative to the H-element about a given center through the aid of clamps 29 and 30.- The clamps are connected to the element through the aid of screws 3i, their inner edges of the clamps being recessed to extend over the largest peripheral portion of the support 20, providing tongue portions 32 and 33 respectively which lie in the recess 2| to serve in holding the support for its movement only about the given center when the clamps are loose and to rigidly secure the support to the element when the clamps are tight. The element 28 is disposed at a given position on asensitive means including an ionization chamber functioning asa result of the X-ray beam tention. is directed to portions 39, 46 and 4| of the crystal, which are portions of natural surfaces thereof. The purpose of the arrange ment shown in Fig. 3 is to determine the x or tained more readily when employing one of the natural faces or surfaces of the crystal. Thus the selected face or surface of the crystal is brought into registration with the X-ray beam otally mounted at 56 upon the part 54 and movable between stop pins 59, is formed for engagement with a projection 60-'made integral with the part 55 for latching the parts of the flask in closed position. The part 55 of the flask is formed with a vertical slot 6| in its comer to receive a mounting plate 62, the latter being identical in structure to the supporting plate 26, it having a recessed periphery 63 and a central tapered aperture 64. In actual structure the supporting plate 20 and the mounting plates 62 are one and the same, a large supply being provided. to serve both functions, they being given additional reference numerals in the present disclosure to properly distinguish the and their functions one from the other. A supporting portion 66, grooved arcuately at 66 to conform to the periphery of the mounting plate 62, is fixed to the portion 65 of the flask or formed integral therewith to cooperate-with the slot 6! to receive and support the mounting plate. The contour of the support 65 causes automatic location of the mounting plate with its aperture 64 in a given position in the flask. Retaining screws 68 are disposed in threaded apertures of the part 55 of the flask and are receivable in elongate depressions or apertures 66 of the deflecting from the crystal. At this point at- This may be obfor registration with the support 20 relative to the portion 39, until there is a deflection of the X-ray beam tocause functioning of the unit 36,

at which time the location of the X orelectric axis will be known. When this has been accomdetermined'and the crystal mounted so that this axis is truly perpendicular to the support 20 and the support with the crystal adjusted so that the X or electric axis will lie in a given position relative to an end surface 43 of the element 26, the structure thus far assembled will be transferred to a table 46 and located in a given position through the aid of a fixed bar 46,

mounted on the table, and a V-block 41 removably disposed in engagement with the bar upon the table. The portion of the block 41 engaging the bar is of a desired thickness and has a surface 46 positioned to be engaged by the end surface 43 of the element 26 for the accurate positioning of the element. An overhanging portion 50 of the V-block 41 has integral members 6! and 52 disposed in planes at right angles with respect to each other and at given angles with respect to the surface 46, for the purpose of locating a molding flask, indicated generally at 53, with respect to the stone l2. 4 Y

The'flask is composed of two main angular parts 54 and "hinged together at 56 for movement into open or closed position, the open. position being shown in Fig. 7 and Figs. 4, 5 and 6 showing theclosed positions. A latch 51, pivmounting plate 62, to anchor the mounting plate in the flask. The apertures 68 function also as spaced locating portions for use in locating the mounting plate and crystal preparatory to the cutting operation. As illustrated in Fig. 6, the edge of the part 54' of the flask is cut away at 16 and conforms, at H, to the mounting plate to cooperate with the adjacent edge of the part 65 of the flask to provide a slot similar to the slot 6| for the projection of the mounting plate there.-

through. Thus when the mounting plate 62 is disposed in place and anchored through the aid of the screws 68 when the flask is closed, the mounting plate is firmly held in position and made a part of the mold or flask structure. This structure, through the aid of the V-block, particularly the members iii and 52 thereof, may be located about the stone l2 upon the support 20. as illustrated in Fig.4.

At this time, through the aid of a marking gage positions locations where these cuts are to be made through the stone. The gage I4 is, then removed and a suitable material prepared for molding the stoneto the mounting plate.

The molding material may be of any suitable type, for example that commercially known as plaster of Paris. "To prepare the flask so that it maybe readily removed from the molded structure, the inner surfaces thereof may be provided with a film of asuitable oil. After the'plaster or molding material 16 has been prepared, the flask may be filled by pouring the material against the sides of the flask so as not to disturb the orientation of the crystal. The flask is fllled with the material, covering the donate a position level with the upper edge of the flask. This assembled structure is left undisturbed for a suitable length of time, such as thirty minutes, after which the flask and the molded structure may be removed from the supporting plate 20. During the given length of time the plaster or molding material has become solidified, and may be handled with care. During the molding of this material, it will be understood that the tapered aperture 84 of the mounting plate has become filled therewith, the outer end of this aperture being closed by the flask part 55, the inner end, however, being open to receive the material. The tapered contour of the aperture assures anchoring of the material therein and anchoring of the inner molded structure including the stone to the mounting plate. The molded structure with the mounting plate may be removed from the flask by sliding the mounting plate relative to the slot 6|. The molded structure may then be set to one side, to thoroughly dry during a period, for example, of six hours, while other stones are being molded.

At the expiration of the drying period, through the aid of the marks 11, previously made upon the mounting plate 82, similar markings 18 may be made upon the surface of the material 16 of the molded structure (Fig. 8), to assist in locating a table 19 of a cutting apparatus rela- The cutting eletive to a cutting element an. ment 8!! is mounted upon a rotatable shaft II which may be driven by any suitable means (not shown); The table 19 includes spaced pins 82, only one of which is shown, these pins being receivable in the recesses or apertures 68 of the mountin plate to accurately locate the molded structure with respect to the cutting element on the table 19. Clamps a: of the table serve in cooperation 'with the annular recess 2| of the mounting plate, to rigidly mount the latter upon the table.

In reviewing the steps of the method through the aid of the apparatus shown, it will be aptal, the adhesive nature of the material assuring maintenance of this mounting although the crystal may be of considerable size and weight, and

regardless of the degree of orientation necessary after this assembly is placed in the bath [5, as shown in Fig. 3. Here the crystal is brought into accurate position with respect to its support 20, causing the optic axis of the crystal to be truly perpendicular to the support.

The next step includes the location of the X or electric axis of the crystal, as illustrated in Fig. 3, without disturbing the location of the crystal upon its support 20. The orientation of the crystal during this step is brought about through the movement of the support 20 relative to the element 28 and the units 81 and 38. It is preferred that this movement be about a point in one of the natural faces of the crystal, or a portion of such, if it exists. Therefore, an X-ray beam is concentrated ata pivot point of the crystal and when the X axis of .the crystal, through the orientation, of the support and crystal, is brought to a given position with respect to and attention is directed to that step at this.

the x-ray beam, this beam will be deflected with its maximum efllciencyto the unit ll. The support is then locked to the element 28, through the aid of the clamps 29 and 30, with respect to the surface 43 of the element.

' At the next step, shown in Fig. 4, through the aid of the V-biock l1 functioning in engagement with the surface 43 of the element and the fixed bar 48, the molding flask 53 is located on the support about the crystal. The mounting plate 62, with its anchoring aperture 64 therein, is disposed in and made a part of the flask ll, located in a given position therein by the portion 85, the locatin aperture'69 being disposed at. a given position with respect to the axis of the crystal through the aid of the screws 88. The moldable material I6, having'been previously prepared, is then poured into the flask. care being taken not to disturb the position of the crystal, the holding effect of the material 23 being sufllcient, however, to retain the crystal positioned against the force of the molding material while being disposed in the flask. The

flask, including the aperture 64, is filled with the material 16 and after the necessary time required for the material to harden, the molded material, with the crystal and the anchored 'mounting plate, is removed from the flask after the flask is opened, as illustrated in Fig. '7,

One step has been eliminated in this review time, it being a marking of the mounting plate as at 11 (Fig. 8) through the aid of the gage H. has been removed from the flask and during this step has also been removed from the support 20,

tals, whether they be of their natural hexagonal contours or of irregular shapes, may be suspended in a material iiwhich will not damage the cutting element but will in many ways aid in the cutting operation. For example, the material 1', will act as a guide to the cutting element, particularly when the element enters the crystal at an irregular surface. The material 18 further reduces chipping of the crystal at the end of the cut, the crystal being supported and backed up by the material 16. The use of the material 16 further eliminates cementing the crystal to the mounting plate or to other materials which require considerable effort in removing, to re-condition the mounting plate for use. Although the material 16 is firmly anchored to the mounting plate after the sawing operations have been completed, the material may be readily broken away, freeing the sections of the crystal and freeing the mounting plate for re-use. Furthermore,'the

material 16 functions as a lubricant for the 'cutting element, which in the present instance is a diamond studded saw.

What is claimed is:

l. The method of cutting quartz crystals comprising supporting a quartz crystal for orientation thereof relative to its support, orienting the crystal relative to its support and axis identifying means to locate certain axes of the crystal ingiven positions relative to the support. locating a mold unit about the crystal with a portion of the mold in a known position relative to certain Thus, after the structure shownin Fig. 8,

of the said axes, placing marks on the said portion in planes where the crystal is to be cut, surrounding the crystal in the unit with e moldable material, allowing the material to harden, placing marks on the material in planes with the aforementioned marks, and cutting the material and the crystal in planes parallel with the marks material, allowing the material to harden, placing marks on the material in planes with the aforementioned marks, and cutting the molded crystal at the marks.

3. The method of cutting quartz crystals comprising securing a quartz crystal to an apertured support at the aperture thereof by a ring of pliable adhesive material, mounting the support with the aperture thereof centrally of a light beam in a means for use in locating a, predetermined axis of the crystal, orienting the crystal,

in the material until the said axis is in a given position relative to the support, orienting the support with the crystal relative to an element and other axis locating means to locate the CI'YS! tal with the second axis thereof in a given position relative to the element, and cutting the crystal in planes disposed at given positions relative to the axes.

4. The method of cutting quartz crystals comprising securing a quartz crystal to an apertured support at the aperture thereof by a ring of pliable adhesive material, mounting the support with the aperture thereof centrally of a light beam in a means for use in locating a predetermined axis -of the crystal, orienting the crystal in the. material until the said axis is in a given position relative to the support, orienting the support with the crystal relative to an element and other axis locating means to locate the crystal with the second axis thereof in a given position relative to the element, locating a molding flask on the support about the crystal and with a portion thereof in a given position aided by the element, surrounding the crystal in the flask with moldable material, removing the'flask, and cutting the molded material and the, crystal in planes disposed at given positions relative ,to the said axes.

"5.; The method of cutting'irregular articles comprising supporting an irregularly surfaced chine, the apparatus comprising a molding flask r the mounting element.

one end of the flask to condition the flask to mold a moldable material, disposed therein, about the crystal and anchor it to the mounting element.

7. An apparatus for preparing quartz crystals for cutting by embedding the quartz crystal in a moldable material anchored to a mounting element, the apparatus comprising a molding flask adapted to receive the mounting element therein and to surround the crystal, means to locate the mounting element in a given position in the flask, and a member for supporting the crystal in the flask and for closing one end of the flask to condition the flask to mold a moldable material, disposed therein, about the crystal and anchor it to 8. An apparatus for preparing quartz crystals ior cutting by embedding th quartz crystal in a moldable material anchored to a mounting element, the apparatus comprising a molding flask adapted to receive the mounting element therein and t surround the crystal, means in the flask to removably receive the mounting element in a given position therein, and a member for supporting the crystal in the flask and for closing one end of the flask to condition the flask to mold a moldable material, disposed therein, about the crystal and anchor it to the mounting element.

9, An apparatus for preparing quartz crystals for cutting by embedding a quartz-crystal in a moldable material anchored in an aperture of a mounting element formed with locating portions for. use in locating the m'ounting element in a given position on a work support of a cutting machine, the apparatus comprising a molding flask adapted to receive the mounting element therein and to surround the crystal, a member for supporting the crystal in the flask and ion closing one end of the flask to condition the flask to mold a moldable material, disposed therein, about the crystal and in the aperture of the mounting element to anchor }the material thereto, and

means cooperating with the said locating portions to locate the mounting element at a given position relative to the crystal. e

10. An apparatus for preparing quartz crystals for cutting by embedding a quartz crystal in a moldable material anchored in an aperture of a mounting element formed with locating portions for use. in locating the mounting element in a given position on a work support of a cutting ma-.

. adapted to removably receive the mounting ale-- article in apliable material, encasing the article in a moldable material, and causing relative movement of theencased article and a cutting element to cause'cutting of the material and article, the material supporting the element against lateral deflections at irregular surfaces of thearticle.

6. An apparatus for preparing quartz crystals for cutting by embedding the quartz'crystal in a moldable material anchored to a. mounting element, theapparatus comprising a molding flask adapted to receive the mounting element therein and to surround the crystal, and a member for I supporting the crystal in the flask and for closing ment therein, close the outer end of the 'said aperture and surround the crystal, and a member, for supporting the crystal in the flask and for closing one end of the flask to condition the flask to'molda moldable material, disposed therein,

about the crystal andinth'e aperture of themounting element to anchor the material thereto.

11. An apparatus for preparing quartz crystals for cutting by embedding a quartz crystal in a moldable material anchored to a portion of a mounting element, the apparatus comprising a molding flask having portions relatively movable into open and closed positions to surround the 7 crystal, one of the portions being formed to remevably receive the element, and a member for supporting the crystal in the flask and for closing one end of the flask to condition the flask to mold a moldable material, disposed therein, about the crystal and in the. aperture of the mounting element to anchor the material thereto. 12. An apparatus. for preparing quartz crystals for cutting by embedding a quartz crystal in a moldable material anchored to a portion of a mountin element, the apparatus comprising a molding flask having portions relatively movable into open and closed positions to surround the crystal, one. 0! the portions being formed to removably receive the element, amember for sup-' porting the crystal in the flask and for closing one end of the flask to condition the flask to mold a moldable material, disposed therein, about the crystal and in the aperture of the mounting elea moldable material, disposed therein, about the 20 crystal and anchor it to the mounting element,

and means to locate the flask in a given position relative to the supporting member to locate the crystal relative to the mounting element.

14. 'A method of cutting quartz crystals comprising connecting a quartz crystalto a support with a tacky pliable material, orienting the crystal in the material relative to its support and an axis identifying means to locate the optic axis 01 the crystal at a given angle relative to the support, locating the electric axis of the crystal at a given position relative to a mounting member, molding the crystal in a material to the mounting member with the optic and electric axes extending in known directions relative to the mounting menher, removing the support and the tacky material, and cuttingthe molded material and crys-y tal at given angles relative to the said axes.

BUR'ION n 

